Technical Data Sheet
| Document | RY-TDS-1105 |
|---|---|
| Revision | Rev. 1.0 |
| Issue date | September 2026 |
| Status | Issued |
Rayson SealForce · Waterproofing membranes
Rayson SealForce WB20 is a one-part, water-based, polyurethane-modified waterproofing membrane for toilets, showers, bathrooms, balconies and other interior wet areas — rolled or brushed on in two coats and concealed beneath the tiles, screed or render.
SealForce WB20 is Rayson's one-part wet-area membrane: a water-based, polyurethane-modified liquid that is stirred and applied straight from the pail, with no mixing ratio to get wrong and no solvent odour in a closed bathroom. Two coats at 0.4 mm wet film each dry to a seamless, flexible green film that follows the floor into the trap, up the wall turn-ups and around every pipe as one continuous membrane.
Standalone coating.
Figure 1 — Typical system build-up (top to bottom). Layer thicknesses are system-dependent; confirm the specification for your project.
| Surface preparation | Substrate must be structurally sound, dry and free of dust, grease, wax, oil, curing compounds and loose material. Remove loose mortar, plaster and any protrusion that could pierce the membrane; clean old concrete with a degreaser and a high-pressure wash and allow it to dry fully. New concrete at least 28 days old; new render at least 7 days. |
|---|---|
| Mixing / dilution | One part — stir gently before use and apply straight from the pail; do not dilute and do not add sand |
| Application method | Roller, Brush |
| Coverage | Approximately 0.56 kg/m² per coat at 0.4 mm wet film (about 1.8 m² per kg); a 20 kg pail covers about 36 m² per coat, or about 18 m² at two coats, subject to substrate condition |
| Application conditions | Apply between 10 °C and 45 °C on a dry substrate. Do not use where negative hydrostatic pressure is evident. Provide falls so water cannot pond on the finished floor. |
| Drying & curing | Touch dry in under 60 minutes; first coat dry in 1–2 hours, second coat in about 4 hours depending on temperature and humidity; ponding test 24 hours after the final coat |
| Recoat interval | 1–2 hours between the first and second coat, depending on temperature and humidity; a third coat where needed to close pinholes. |
| Film / thickness | Minimum two coats at 0.4 mm wet film each (about 0.56 kg/m² per coat); green film — coverage and missed spots show clearly. |
| Pack sizes | 20 kg plastic pail |
| Storage | Store in original, unopened, undamaged and sealed packaging in dry conditions, away from direct sunlight and frost. |
| Shelf life | 12 months from the date of production. |
Figure 2 — Application workflow. Each stage is a hold point: confirm the previous stage is complete and within specification before proceeding.
Toilet or bathroom waterproofing before tiling
Balcony or terrace beneath screed and tiles
Low-odour water-based product. Wear gloves and eye protection; ensure reasonable ventilation. Avoid skin and eye contact. Keep out of reach of children. Consult the Safety Data Sheet (in preparation) before use.